Ink jet recording apparatus

ABSTRACT

An ink jet recording apparatus for expelling an ink from a print head (1) toward a recording medium (2) to form an image thereon has a fixing solution head (10) for forming on the recording medium (2) a dye acceptor layer composed of an intercalation compound which fixes and holds a dye of the ink by way of an intercalation. The fixing solution head (10) expels a solution (fixing solution) containing the intercalation compound. The ink jet recording apparatus is capable of forming images of excellent water resistance and light resistance.

TECHNICAL FIELD

The present invention relates to an ink jet recording apparatus having ameans for forming on a recording medium a dye acceptor layer which fixesand holds a dye by way of an intercalation.

BACKGROUND ART

One of the methods of outputting images such as documents, graphicrepresentations, or the like generated by personal computers or the likeonto recording mediums such as sheets of paper, OHP films, or the likeis known as an ink jet recording process.

In the ink jet recording process, an ink in the form of a solution isejected from a nozzle toward a recording medium by a drive source whichemploys an electric field, heat, pressure, or the like for therebyforming an image on the recording medium. The ink jet recording processis advantageous in that it produces a low level of noise, requires a lowrunning cost, can form images on sheets of ordinary paper, and does notdischarge a waste material such as ink ribbons. Therefore, ink jetrecording apparatus have been finding widespread use in recent years asrecording apparatus for office or personal use.

The ink jet recording process is, however, disadvantageous in thatimages formed on recording media by this process have poor fixabilityproperties, particularly water resistance and light resistance.

The reasons for such poor fixability properties are as follows:Generally, an ink for use in ink jet recording is composed of awater-soluble dye. For printing using such an ink, the ink is ejectedtoward a recording medium, and after the ink has been dried, itswater-soluble dye remains on the recording medium and is held thereon bythe van der Waals forces or hydrogen bonding for thereby fixing an imageto the recording medium. Therefore, when a solvent such as water or thelike which has a large affinity for the water-soluble dye is supplied tothe recorded image, the dye is eluted, causing the image to blur.

The dye also moves, causing the image to blur, when the water-solubledye which forms the image on the recording medium is supplied withthermal or light energy that is large enough to cancel out the van derWaals forces or hydrogen bonding between the dye and the recordingmedium. Furthermore, upon exposure of the dye which forms the image tolight such as ultraviolet radiation or the like, the molecules of thedye itself are destroyed, causing the image to be faded, discolored, orlowered in density. Therefore, images formed by the dye are also of lowlight resistance.

The water resistance of images formed according to the ink jet recordingprocess can be improved by using a recording medium of sized paper or arecording medium coated with a resin. The resin to be coated on therecording medium comprises a hydrophilic resin for allowing an image tobe formed by a water-soluble dye. Attempts have also been made toimprove the light resistance of images formed according to the ink Jetrecording process by selecting a dye having a certain basic skeleton orintroducing a certain substituent group into a side chain of dyemolecules thereby to limit the molecular structure of the dye.

If the recording medium of sized paper is used to improve the waterresistance of images formed according to the ink jet recording process,then it takes a long time to fix the ink to the recording medium as therecording medium has low ink absorption.

If the recording medium coated with a hydrophilic resin is used, then ithas good ink absorption, but tends to form ink dots of large diameter orink dots having blurred edges. Since the resin coated on the recordingmedium is hydrophilic, it essentially is not sufficiently effective toimprove the water resistance of recorded images. Another problem of therecording medium coated with a hydrophilic resin is that it impairs thebasic advantage of the ink jet recording process that sheets of ordinarypaper can be used as the recording medium.

The attempts to limit the molecular structure of the dye for improvedlight resistance have not yet been sufficiently effective.

The present invention has been made to solve the above problems of theprior art.

It is an object of the present invention to form images of high waterand light resistance on sheets of ordinary paper according to an ink jetrecording process.

DISCLOSURE OF THE INVENTION

The inventor has found that in order to achieve the above object, a dyeacceptor layer composed of an intercalation compound for holding a dyeby way of an intercalation may be formed on a recording medium such asof plain paper, that a means for forming such a dye acceptor layer maybe included in an ink jet recording apparatus, that the dye acceptorlayer may be formed by expelling or spraying a solution (hereinafterreferred to as a fixing solution) containing such an intercalationcompound from a nozzle or nozzles, or coating a fixing solution on therecording medium with a coating roller, or electrostatically applying apowder (referred to as a clay powder in this specification) composed ofan intercalation compound and a thermoplastic resin to the recordingmedium, or producing a ribbon having a dye acceptor layer composed of anintercalation compound and formed on a base film and thermallytransferring the dye acceptor layer of the ribbon onto the recordingmedium, or melting a fixing agent which is composed of an intercalationcompound and a wax and solid at normal temperature (hereinafter referredto as a solid fixing agent) and coating the melted fixing agent on therecording medium, and has completed the present invention.

According to the present invention, an ink jet recording apparatushaving an ink nozzle for expelling an ink toward a recording medium toform an image thereon is characterized by a dye acceptor layer formingmeans for forming on said recording medium a dye acceptor layer composedof an intercalation compound which fixes and holds a dye of the ink byway of an intercalation.

The ink jet recording apparatus according the present invention willhereinafter be described in detail.

In the ink jet recording apparatus according the present invention, animage is fixed on the basis of the formation of an ionic bond caused byan intercalation between a dye in the ink and the intercalation compoundof the dye acceptor layer.

The ink may be prepared by dissolving a dye into an aqueous solvent suchas water or the like, and adding, if necessary, a viscosity modifier, asurface tension modifier, a drying inhibitor, and so on to the solution.Any of the various inks that have conventionally been used for an inkjet recording apparatus may be used.

An acid dye, a direct dye, a basic dye, or the like may be used withoutany particular limitations as the dye to be contained in the ink insofaras it can be intercalated into the intercalation compound. For example,a basic dye such as an azo dye having an amine salt or a quaternaryammonium group, a triphenylmethane dye, an azone dye, an oxazine dye, athiazine dye, or the like may be used. More specifically, a yellow dyesuch as C.I. basic yellow 1, C.I. basic yellow 2, C.I. basic yellow 11,C.I. basic yellow 13, C.I. basic yellow 14, C.I. basic yellow 19, C.I.basic yellow 21, C.I. basic yellow 25, C.I. basic yellow 28, or C.I.basic yellow 32˜36; a magenta dye such as C.I. basic red 1, C.I. basicred 2, C.I. basic red 9, C.I. basic red 12˜15, C.I. basic red 17, C.I.basic red 18, C.I. basic red 22˜24, C.I. basic red 27, C.I. basic red29, C.I. basic red 32, C.I. basic red 38˜40; C.I. basic violet 7, C.I.basic violet 10, C.I. basic violet 15, C.I. basic violet 21, C.I. basicviolet 25˜28; a cyan dye such as C.I. basic blue 1, C.I. basic blue 3,C.I. basic blue 5, C.I. basic blue 7, C.I. basic blue 9, C.I. basic blue19, C.I. basic blue 21, C.I. basic blue 22, C.I. basic blue 24˜26, C.I.basic blue 28, C.I. basic blue 29, C.I. basic blue 40, C.I. basic blue41, C.I. basic blue 44, C.I. basic blue 45, C.I. basic blue 47, C.I.basic blue 54, C.I. basic blue 58˜60, C.I. basic blue 64˜68, or C.I.basic blue 75; and a black dye such as C.I. basic black 2, or C.I. basicblack 8 may be used.

The dye acceptor layer to be formed on the recording medium in order tofix the above dye should preferably be composed of a high-polymerorganic intercalation compound having exchangeable negative ions betweenlayers if the ink is composed of an acid dye or a direct dye, or ahigh-polymer organic intercalation compound having exchangeable positiveions between layers if the ink is composed of a basic dye.

The intercalation compound has a laminar structure and holdsinterlaminar water and exchangeable ions between layers. Thehigh-polymer inorganic intercalation compound having exchangeablepositive ions between layers which is used if the ink is composed of abasic dye may be natural or synthetic laminar silicate or their sinteredmaterial. Typically, it is preferable to use a montmorillonite-groupmineral which is a clay mineral having a 3-octahedral smectite structureand represented by the following formula (1):

    (X, Y).sub.2-3 Z.sub.4 (.sub.10 (OH.sub.2)·mH.sub.2 O·(W.sub.1/3)                                    (1)

where X represents Al, Fe(III), Mn(III), or Co(III), Y represents Mg,Fe(II), Ni, Zn, or Li, Z represents Si or Al, W represents K, Na, or Ca,H₂ O represents interlaminar water, and m represents an integer.

Depending on the combination of X and Y and the number of substitutions,the montmorillonite-group mineral may be a natural or synthetic mineralsuch as montmorillonite, magnesia montmorillonite, iron montmorillonite,iron magnesia montmorillonite, beidellite, aluminianbeidellite,nontronite, aluminiannontronite, saponite, aluminiansaponite, hectorite,sauconite, or the like. Materials represented by the above formula (1)with the OH group replaced with fluorine may also be used.

Other than the montmorillonite-group mineral represented by the aboveformula (1), a mice-group mineral such as sodium silicic mica, sodiumteniorite, lithium teniorite, or the like may also be used as anintercalation compound.

The high-polymer inorganic intercalation compound having exchangeablenegative ions between layers which is used if the ink is composed of anacid dye or a direct dye may be hydrotalcite or the like.

Depending on the type of the ink used, the dye acceptor layer to beformed on the recording medium may contain an intercalation compoundhaving exchangeable positive ions, such as montmorillonite or the like,or an intercalation compound having exchangeable negative ions, such ashydrotalcite or the like, or both of these intercalation compounds.

The present invention is not limited to any method of forming a dyeacceptor layer composed of such an intercalation compound. In an exampleof such a method, a fixing solution, i.e., a solution containing anintercalation compound, is prepared, and ejected from a solution nozzleonto a recording medium to form a dye acceptor layer.

The fixing solution may be expelled from the solution nozzle as dropletshaving the same shape as ink droplets expelled from ink nozzles, or maybe atomized and expelled (sprayed) from the solution nozzle.

Specifically, the solution nozzle may comprise a single nozzle, and thefixing solution may be sprayed from the nozzle in a range covering animage that will be formed by expelling the ink from the ink nozzles ontothe recording medium.

Alternatively, the solution nozzle may comprise an array of nozzles, andfixing solution may be sprayed from the nozzles in a range of an imagethat will be formed by expelling the ink from the ink nozzles onto therecording medium. If the ink nozzle comprises a plurality of nozzlesarranged in the same manner as the nozzles of the solution nozzle, thenthe nozzles of the solution nozzle are selectively operable to spray thefixing solution in a manner to correspond to those of the nozzles of theink nozzle which expel the ink.

The solution nozzle may also comprise a nozzle in the form of an oblonghole for spraying the fixing solution in a range covering an image thatwill be formed by expelling the ink from the ink nozzles onto therecording medium.

The fixing solution may be prepared by mixing an intercalation compoundwith an aqueous solvent such as water, alcohol, or the like, and adding,if necessary, an additive such as a binder resin, a dispersionstabilizer, an ultraviolet light absorber, or a fluorescent brightener.

Alternatively, a powder (clay powder) composed of an intercalationcompound and a thermoplastic resin may be prepared, and a dye acceptorlayer may be formed on the recording medium using such a clay powder.

The clay powder may be prepared by dispersing a powdery intercalationcompound into a thermoplastic resin binder, and converting thedispersion into a fine powder. The thermoplastic resin binder into whichthe powdery intercalation compound is to be dispersed may be composed ofa stylene - acryl copolymer, polyester, an epoxy resin, or the like, forexample.

As the thermoplastic resin to be used as the binder resin, it ispreferable not to contain a group which will impair an intercalationbetween an intercalation compound and a dye, e.g., an ammonium group orthe like which is more likely held between layers than the dye.

Since use of a certain intercalation compound and a certain binder resinin combination makes it possible to produce a highly transparent dyeacceptor layer, the intercalation compound and the binder resin shouldbe selected depending on the degree of transparency which is required bythe recording medium after an image has been formed thereon.

A dye acceptor layer may be formed on a recording medium using a claypowder in the same manner as a toner is applied to a recording medium toform an image thereon according to the electrophotographic process.Specifically, the clay powder may be electrostatically attracted to therecording medium, and then heated so as to be fixed to the recordingmedium. Alternatively, a clay powder may be dispersed in an insulatingsolvent such as of dibutyl phthalate or the like, thus producing a clayliquid, and the clay liquid may be attracted to a recording medium inthe same manner as a liquid toner image is developed according to theelectrophotographic process, for thereby forming a dye acceptor layer.

A dye acceptor layer composed of an intercalation compound may be formedon a recording medium by producing a ribbon having a dye acceptor layercomposed of an intercalation compound and a binder resin and formed on abase film made of polyethylene terephthalate or the like, and thermallytransferring the dye acceptor layer of the ribbon onto the recordingmedium.

To the dye acceptor layer of the ribbon, there may be added aplasticizer for controlling the glass transition point Tg thereof unlessit does not impair the transferability thereof to the recording medium.Furthermore, an additive for controlling the water repellancy, anultraviolet light absorber for improving the light resistance, afluorescent brightener, and so forth may also be added. In theproduction of the ribbon, because use of a certain intercalationcompound and a certain binder resin in combination makes it possible toproduce a highly transparent dye acceptor layer, the intercalationcompound and the binder resin should be selected depending on the degreeof transparency which is required by the recording medium after an imagehas been formed thereon.

If the dye acceptor layer is thermally transferred from the ribbon toform the dye acceptor layer on the recording medium, then the recordingmedium should preferably be of such a nature as to be prevented frombeing deformed with the heat when the dye acceptor layer is thermallytransferred thereonto.

A dye acceptor layer composed of an intercalation compound may also beformed on a recording medium by preparing a fixing agent which iscomposed of an intercalation compound and a wax and solid at normaltemperature (solid fixing agent) and coating the melted fixing agent onthe recording medium. The wax which serves as a binder for theintercalation compound may be carnauba wax, paraffin wax, high-polymerpolyethylene glycol, or the like, for example.

In the preparation of a solid fixing solution from a wax and anintercalation compound, depending on the type of the wax used, theability of the produced solid fixing solution to absorb the ink would belowered if the proportion of the wax were too high, and the solid fixingagent would not be solid at normal temperature if the proportion of thewax were too low. Therefore, the ratios of the wax and the intercalationcompound are determined such that the produced solid fixing solution canwell absorb the ink and become solid at normal temperature. For example,if a solid fixing agent is prepared from carnauba wax and syntheticsmectite whose ratios are 1:1, then the produced solid fixing solutionis hydrophilic and has a good ability to absorb an aqueous ink.Increasing the ratio of the carnauba wax makes the solid fixing agentmore hydrophilic. The solid fixing solution can be obtained at roomtemperature with a ratio of the carnauba wax and synthetic smectite upto about 1:5. If a solid fixing agent is prepared from high-polymerpolyethylene glycol and synthetic smectite, then the ability of theproduced solid fixing solution to absorb the ink is not reduced by anincrease in the proportion of the high-polymer polyethylene glycol.

In the ink jet recording apparatus according to the present invention,an ink is expelled from the ink nozzles to form an image on therecording medium, and a dye acceptor layer composed of an intercalationcompound is formed on the recording medium by the dye acceptor layerforming means.

When the ink image is formed on the dye acceptor layer which is formedon the recording medium by the dye acceptor layer forming means or thedye acceptor layer is formed on the ink image by the dye acceptor layerforming means, dye ions in the ink are transferred, together with waterand alcohol in the ink, between layers of the intercalation compound ofthe dye acceptor layer, and exchanged (intercalated) with interlaminarions that have been present between the layers, so that the dye ions arefirmly held between the layers by an ionic bond with the intercalationcompound.

The dye thus held between the layers will not be eluted even whensupplied with water or the like. Consequently, the image produced by theink jet recording apparatus according to the present invention hasincreased water resistance. The dye trapped between the layers is notdirectly exposed to external light, and hence the light resistance ofthe image formed by the ink jet recording apparatus according to thepresent invention is highly increased.

A highly transparent dye acceptor layer can be formed on a recordingmedium if a certain intercalation compound and a certain binder resinare used in combination. Therefore, a preferable image can be formed ona recording medium that is required to be transparent for OHP use, forexample.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing in its entirety an ink jet recording apparatusaccording to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a portion in the vicinity of headsof the ink jet recording apparatus according to the embodiment shown inFIG. 1;

FIG. 3 is a view illustrative of ink nozzles of the heads of the ink jetrecording apparatus according to the embodiment shown in FIG. 1;

FIG. 4 is a view illustrative of an intercalation;

FIG. 5 is a view showing the manner in which an ink is fixed and held byway of an intercalation;

FIG. 6 is a view showing in its entirety an ink jet recording apparatusaccording to another embodiment of the present invention;

FIG. 7 is a perspective view showing another arrangement of a fixingsolution head 10;

FIG. 8 is a view illustrative of a range of a fixing solution sprayedfrom the fixing solution head 10 shown in FIG. 7;

FIG. 9 is a side elevational view of the fixing solution head 10 shownin FIG. 7;

FIG. 10 is a perspective view showing still another arrangement of thefixing solution head 10;

FIG. 11 is a view illustrative of a range of a fixing solution sprayedfrom the fixing solution head 10 shown in FIG. 10;

FIG. 12 is a perspective view showing yet still another arrangement ofthe fixing solution head 10;

FIG. 13 is a view illustrative of a range of a fixing solution sprayedfrom the fixing solution head 10 shown in FIG. 12;

FIG. 14 is a view illustrative of the manner in which the fixingsolution head 10 shown in FIG. 12 operates;

FIG. 15 is a view illustrative of the manner in which the fixingsolution head 10 shown in FIG. 12 operates;

FIG. 16 is a view showing in its entirety an ink jet recording apparatusaccording to still another embodiment of the present invention;

FIG. 17 is a view showing in its entirety an ink jet recording apparatusaccording to yet still another embodiment of the present invention;

FIG. 18 is a view showing in its entirety an ink jet recording apparatusaccording to a further embodiment of the present invention;

FIG. 19 is a view showing in its entirety an ink jet recording apparatusaccording to a still further embodiment of the present invention;

FIG. 20 a view showing in its entirety an ink jet recording apparatusaccording to a yet still further embodiment of the present invention;

FIG. 21A and 21B are views illustrative of the manner in which a dyeacceptor layer X formed in a ribbon P is thermally transferred onto arecording medium 2;

FIG. 22 a perspective view showing in its entirety an ink jet recordingapparatus according to another embodiment of the present invention;

FIG. 23 is a perspective view showing in its entirety an ink jetrecording apparatus according to still another embodiment of the presentinvention;

FIG. 24 is a perspective view showing in its entirety an ink jetrecording apparatus according to yet still another embodiment of thepresent invention;

FIG. 25 is a cross-sectional view of the ink jet recording apparatusaccording to the embodiment shown in FIG. 24; and

FIG. 26 is a cross-sectional view of an ink jet recording apparatusaccording to a further embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will hereinafter be described inspecific detail with reference to the drawings. Identical referencecharacters denote identical or equivalent components throughout views.

FIG. 1 is a view showing in its entirety an ink jet recording apparatusaccording to an embodiment of the present invention, the ink jetrecording apparatus comprising a so-called serial ink jet printer havinga dye acceptor layer forming means for discharging a fixing solution Lto form a dye acceptor layer. FIG. 2 is a view of a portion in thevicinity of heads of the recording apparatus shown in FIG. 1, as viewedin cross section. FIG. 3 is a view illustrative of ink nozzles of theheads of the ink jet recording apparatus.

In the serial ink jet printer, as shown in FIGS. 1 and 2, a print head 1having ink nozzles 6 (see FIG. 3) for expelling an ink is reciprocallyscanned in the transverse direction (indicated by the arrow x) of arecording medium 2 of paper, plastic film, cloth, or the like while therecording medium 2 is being fed in the direction indicated by the arrowy, for thereby printing an image on the recording medium 2.

The print head 1 is supported on a shaft 3 and caused to scan therecording medium by a belt 5 which is trained around a head feed motor4. The print head 1 may be of the type which produces an ink expellingpressure by either deforming a so-called piezoelectric element, orboiling an ink with a heating element, or using an electric field. Asshown in FIG. 3, the print head 1 has an array of ink nozzles 6perpendicular to the scanning direction thereof.

While the print head 1 usually has such a plurality of ink nozzles, itmay have a single nozzle.

The recording medium 2 is fed by a sheet feed roller 8 which is rotatedby a sheet feed motor 7.

In this embodiment, the serial ink jet printer has a fixing solutionhead 10 movable in the scanning direction of the print head 1, thefixing solution head 10 having fixing solution nozzles 9 for expelling afixing solution L to form a dye acceptor layer. The fixing solutionnozzles 9 are located in positional one-to-one correspondence to the inknozzles 6.

The fixing solution head 10 is arranged to expel, from the fixingsolution nozzles 9, droplets of the fixing solution L which are ofsubstantially the same shape as ink droplets (having a diameter rangingfrom 30 to 100 μm, for example) that are expelled from the ink head 1.

The serial ink jet printer includes a heater 11 disposed on one side ofthe recording medium 2 opposite to the fixing solution head 10 and theprint head 1 and serving as a drying means for drying the fixingsolution L expelled from the fixing solution head 10 and the inkexpelled from the print head 1. The heater 11 comprises a lamp 11a and areflecting plate 11b. The drying means may not necessarily be requiredin this embodiment, but may be employed if necessary when the rate atwhich the fixing solution L and the ink dry is too low. In FIG. 2, thedrying means is positioned such that the heater 11 is disposed directlybelow the print head 1. However, the heater 11 may not necessarily bedisposed directly below the print head 1.

The recording apparatus according to this embodiment is used as follows:An ink is prepared by mixing 2 parts by weight of a basic dye, 2 partsby weight of glycerin, 6 parts by weight of diethylene glycol, and 30parts by weight of water. A fixing solution L is prepared by charging 90g of montmorillonite into 850 g of an ethanol solvent which contains 10g of polyvinyl butyral, dispersing the montmorillonite into the ethanolsolvent for one day, and then mixing 50 g of an ethanol solvent whichcontains 10 g of glycerin into the dispersion. The ink and the fixingsolution L are then set in the recording apparatus. For printing,droplets of the fixing solution L which are of substantially the samediameter as the fixing solution nozzles 9 of the fixing solution head 10are expelled from the fixing solution nozzles 9 to print a desiredcharacter or a graphic representation on the recording medium or toprint a solid blank pattern on the recording medium. The fixing solutionL permeates the fibers of the recording medium 2 which may be made ofpaper or the like, and is dried, whereupon the montmorillonite containedin the fixing solution L is attached nearly to the surface of therecording medium 2.

Then, droplets of the ink which are of substantially the same diameteras the ink nozzles 6 of the print head 1 are expelled from the inknozzles 6 to print a desired character or a graphic representation onthe recording medium. As shown in FIG. 4, the basic dye contained as dyeions in the ink and the water as a solvent are quickly transferredbetween layers of the montmorillonite as an intercalation compound, andan exchange between dye cations (dye ions) and intercalation positiveions (intercalation ions), i.e., an intercalation, occurs, causing thedye to be trapped between the layers of the montmorillonite. The dyetrapped between the layers of the montmorillonite is combined with themontmorillonite by an ionic bond, resulting in a chemically highlystable state.

FIG. 5 is a cross-sectional view of the recording medium 2, showing themanner in which printing is carried out by fixing and holding the ink asdescribed above. On the surface of the recording medium 2, there isformed a dye acceptor layer composed of the intercalation compound bythe fixing solution. When droplets of an ink (ink droplets) are suppliedand attached to the dye acceptor layer, the ink droplets enter betweenthe layers of the intercalation compound by way of an intercalation.

Therefore, the attached dye is prevented from being eluted from orswelling between the layers in the presence of water or a organicsolvent, so that the water resistance of an image that is formed by thedye is greatly increased. Furthermore, the light resistance of the imageis also highly increased because the dye trapped between the layers isshielded from direct exposure to external light.

The ink may comprise an acid dye or a direct dye, and the fixingsolution may comprise hydrotalcite. According to such a modification,the acid dye or the direct dye is quickly transferred between layers ofthe hydrotalcite, and an exchange between dye anions and intercalationnegative ions, i.e., an intercalation, takes place.

In the use of the recording apparatus, a desired character or image maybe printed with the ink and then with the fixing solution, rather thanbeing printed with the fixing solution and then with the ink asdescribed above.

In the use of the recording apparatus, furthermore, the rate at whichthe fixing solution L and the ink dry may be increased, if necessary, bythe heater 11. The rate at which the fixing solution L and the ink drymay be increased by heating the recording medium 2 either in advance ofprinting or subsequent to printing.

FIG. 6 is a view showing in its entirety an ink jet recording apparatusin its entirety according to another embodiment of the presentinvention, the ink jet recording apparatus comprising a dye acceptorlayer forming means according to the present invention. The recordingapparatus according to this embodiment includes a print head 1 havingink nozzles 6 and a fixing solution head 10 having fixing solutionnozzles 9, the print head 1 and the fixing solution head 10 beingstaggered in an auxiliary scanning direction. The other details of therecording apparatus according to this embodiment are identical to thoseof the recording apparatus according to the embodiment shown in FIG. 1.

In the recording apparatus according to the present invention, the printhead 1 and the fixing solution head 10 may thus be switched around inposition, and are not limited to any particular positions. Therefore,the print head 1 and the fixing solution head 10 in the recordingapparatus according to the embodiments shown in FIGS. 1 and 6 may beswitched around in position.

The fixing solution head 10 may be arranged as shown in the perspectiveview of FIG. 7. In this arrangement, the fixing solution head 10 has asingle fixing solution nozzle 9, and a spray of fixing solution L(composed of droplets having a diameter of several μm or less, forexample) is ejected (sprayed) from the fixing solution nozzle 9 by asolution spray device (not shown) that is actuated by a drive sourcewhich employs an electric field, heat, pressure, or the like.

The fixing solution L is sprayed in a conical shape from the fixingsolution nozzle 9, and a circular pattern (shown hatched in FIG. 7) ofthe fixing solution D which is formed on the recording medium 2 by beingthus sprayed covers a range in which the ink expelled from the array ofink nozzles 6 is attached to the recording medium 2 as shown in FIG. 8.

The recording apparatus according to the embodiment shown in FIG. 7 isshown in side elevation in FIG. 9 as viewed from the fixing solutionhead 10.

Each time the print head 1 and the fixing solution head 10 are scanned,the fixing solution L is sprayed from the fixing solution nozzle 9 andattached to the recording medium 2 along each line thereon.

Since the fixing solution L is applied in a thin layer uniformly withoutirregularities to the recording medium 2, variations (irregularities) ofthe thickness of the recording medium 2 which are produced by theattached fixing solution are reduced. Furthermore, the amount of thefixing solution L which is used is also reduced.

If the print head 1 does not print one line in one cycle, but prints oneline in a plurality of cycles, i.e., if a line feed interval or pitchcorresponds to one of the eight ink nozzles 6 shown in FIG. 7 and henceone dot is printed in eight superposed cycles, then the fixing solutionnozzle 9 of the fixing solution head 10 sprays the fixing solution Lonly in the first scanning stroke, for example, of eight scanningstrokes of the print head 1 which are carried out per line.

If the fixing solution L is sprayed in a circular pattern in eachscanning stroke of the print head 1 and the fixing solution head 10 inorder to cover the range in which the ink is expelled from the inknozzles 6, as shown in FIG. 8, then the fixing solution L is coated inmany superposed layers on the recording medium 2 in the scanningdirection of the print head 1 and the fixing solution head 10.

Moreover, in starting and ending zones of the scanning strokes of theprint head 1 and the fixing solution head 10 for one line, the fixingsolution is sprayed onto the recording medium 2 at areas where noprinting is effected. Specifically, zones where one line starts and endscontain areas where no printing is effected with the fixing solution Lbeing left applied in semicircular patterns.

To avoid such a problem, the fixing solution head 10 may be arranged asshown in FIG. 10. In FIG. 10, the fixing solution head 10 has a fixingsolution nozzle 9 defined in the form of an oblong hole. As shown inFIG. 11, the fixing solution nozzle 9 sprays a fixing solution L in asubstantially minimum pattern surrounding the range in which the inkexpelled from all the ink nozzles 6 is attached to the recording medium2.

Since no fixing solution L is applied in superposed layers or no fixingsolution L is attached to areas in which no printing is effected by theprint head 1, the amount of the fixing solution L used is also reduced.Furthermore, inasmuch as the fixing solution L is uniformly applied tothe recording medium 2, the finished appearance of the recording mediumis improved.

The fixing solution nozzle 9 may be of a vertically elongate shape suchas a rectangular shape or a linear shape, rather than the shape of anoblong hole.

FIG. 12 shows yet still another arrangement of the fixing solution head10. The fixing solution head 10 has fixing solution nozzles 9 definedtherein at positions that are held in positional one-to-onecorresponding to the ink nozzles of the print head 1. As shown in FIG.13, the fixing solution nozzles 9 spray a fixing solution L insubstantially minimum ranges that surround areas in which the inkexpelled from the respective ink nozzles 6 is attached to the recordingmedium 2, i.e., respective dots.

At this time, the fixing solution L may be sprayed from all the fixingsolution nozzles 9 at all times. However, the fixing solution L may besprayed selectively from only those of the fixing solution nozzles 9which correspond to those ink nozzles 6 that expel the ink.

Specifically, as shown in FIG. 14, if the ink is expelled from first,third, and eighth ink nozzles 6, as counted from above, of all the inknozzles 6, then the fixing solution L is also sprayed from first, third,and eighth fixing solution nozzles 9 as counted from above. In thisarrangement, the fixing solution L is applied to only those areas whereprinting is effected by the print head 1, as shown in FIG. 15, so thatthe amount of the fixing solution L used is greatly reduced.

The ranges where the sprayed fixing solution L is attached to therecording medium 2 may be adjusted by varying the shape and size of thespray ports of the fixing solution nozzles 9 or the pressure under whichthe fixing solution L is sprayed. The ranges may also be adjusted byvarying the distance between the fixing solution head 10 and therecording medium 2 or tapering inner side surfaces of the fixingsolution nozzles 9.

In spraying the fixing solution L in the manner described above, thesequence in which the ink and the fixing solution L are applied and thepositions of the print head 1 and the fixing solution head 10 are notlimited to any particular configuration, as is the case with theembodiments shown in FIGS. 1 through 3 and 6.

To use the recording apparatus for spraying the fixing solution L asdescribed above, the fixing solution L was produced as follows: 75 g ofsynthetic smectite (tradename "SWN" manufactured by Coop Chemical Co.Ltd.) was charged into 400 g of an ethanol solution containing 25 g ofpolyvinyl butyral (tradename "BL-1" manufactured by Sekisui ChemicalCo., Ltd.), and dispersed therein by a roll mill for two days. Then, 150g of an ethanol solution containing 30 g of diethylene glycol was addedto the dispersion, and dispersed therein for one day, thereby producinga fixing solution L.

The ink to be used in the recording apparatus was prepared according toa composition as follows:

    ______________________________________                                        (Ink composition)                                                             ______________________________________                                        Basic dye           2 parts by weight                                         Glycerin            2 parts by weight                                         Diethylene glycol   6 parts by weight                                         Water              30 parts by weight.                                        ______________________________________                                    

Basic dyes for respective colors Y, M, C, B were as follows: (Dyes)

Y: C. I. basic yellow 51

M: C. I. basic red 46

C: C. I. basic blue 75

B: C. I. basic black 2.

FIG. 16 is a view showing in its entirety an ink jet recording apparatusaccording to still another embodiment of the present invention. The inkjet recording apparatus according to this embodiment comprises a serialink jet printer having a dye acceptor layer forming means according thepresent invention. However, rather than expelling (the term has a widesense including spraying) a fixing solution L from nozzles onto arecording medium 2 to form a dye acceptor layer, the fixing solution Lis coated on the recording medium 2 by a coating roller 13 to form a dyeacceptor layer on the recording medium 2.

Specifically, the recording apparatus shown in FIG. 16 comprises afixing solution coating section A, a drying section B, and a printingsection C. The fixing solution coating section A has a solutionreservoir 12 for holding a fixing solution L therein, a coating roller13 for coating the fixing solution L on a recording medium 2, and acounter-roller 14 disposed opposite to the coating roller 13. The dryingsection B has an oven 17 comprising a heater 15 and a reflecting plate16. The printing section C has a print head 1 for expelling an ink.

To use the recording apparatus shown in FIG. 16, a fixing solution L isplaced in the solution reservoir 12 in advance. The coating roller 13 isuniformly wetted with the fixing solution L. When the recording medium 2is fed in the direction indicated by the arrow D and gripped between thecoating roller 13 and the counterroller 14, the fixing solution L on thecoating roller 13 is transferred onto the recording medium 2 which isnow uniformly wetted with the fixing solution L. The recording medium 2that is coated with the fixing solution L is fed through guides 18 intothe drying section B in which the recording medium 2 is dried by theoven 17, thus forming a dye acceptor layer X on the recording medium 2.Thereafter, an ink is ejected from the print head 1 to form an image onthe recording medium 2 in the same manner as described above withrespect to the recording medium according to the embodiment shown inFIGS. 1 through 3.

In this embodiment in which the fixing solution L is coated on therecording medium 2 by the coating roller 13, the fixing solution L maybe coated on the recording medium 2 after it is printed by the ink,rather than printing the recording medium 2 after it is coated with thefixing solution L. In the recording apparatus shown in FIG. 16, the oven17 is positioned on the same side of the recording medium 2 as the printhead 1, the oven 17 may be positioned on the opposite side of therecording medium 2. The oven 17 may be replaced with a heat roller orthe like. The drying section B may be dispensed with depending on therate at which the fixing solution L dries.

FIG. 17 is a view showing an ink jet recording apparatus according toyet still another embodiment of the present invention, the ink jetrecording apparatus having a dye acceptor layer forming means forforming a dye acceptor layer using a clay powder M.

The ink jet recording apparatus according to the embodiment shown inFIG. 17 comprises, as the dye acceptor layer forming means, a claypowder reservoir 19 for holding a clay powder M, a clay drum 20 forattaching the clay powder electrostatically to a recording medium 2, apowder cutting blade 21 for keeping constant the height of the claypowder M attached to the clay drum 20, a clay attaching roller 22 forcharging the recording medium 2 to a potential opposite to that of theclay powder M to attach the clay powder M to the recording medium 2, andfixing rollers 23 for heating the clay powder M attached to therecording medium 2 to fix the clay powder M to the recording medium 2.The fixing rollers 23 may have halogen lamps or the like disposedtherein for heating the clay powder M to a temperature ranging fromabout 150° to 200° C.

A print head 1 having ink jet nozzles is disposed subsequently to thedye acceptor layer forming means.

To use the ink jet recording apparatus shown in FIG. 17, a clay powder Mand a carrier (iron powder) are placed in the clay powder reservoir 19.Then, while a bias potential (e.g., -3˜-4 kV) is being applied to theclay drum 20 and a bias potential (e.g., +3˜+4 kV) is being applied tothe clay attaching roller 22, the clay drum 20 is rotated totriboelectrically charge the clay powder M and the carrier to respectiveopposite polarities. When the recording medium 2 is fed between the claydrum 20 and the clay attaching roller 22, the clay powder M on the claydrum 20 is attached under electrostatic forces to the recording medium 2that has been charged to the polarity opposite to the clay powder M bythe clay attaching roller 22. Then, the clay powder M attached to therecording medium 2 is heated by the fixing rollers 23 and hence fixed tothe recording medium 2. In this manner, a dye acceptor layer X composedof an intercalation compound is formed on the recording medium 2.Thereafter, an ink is expelled from the print head 1 to form an image onthe recording medium 2 with the dye acceptor layer X formed thereon.

FIG. 18 shows a modification of the ink jet recording apparatus shown inFIG. 17. In the ink jet recording apparatus shown in FIG. 18, after theclay powder M is attached to the recording medium 2 and before it isfixed by the fixing rollers 23, an image is formed on the recordingmedium 2 with an ink by the print head 1. Thereafter, the clay powder Mis fixed by the fixing rollers 23, forming a dye acceptor layer X. Theother details of the ink jet recording apparatus shown in FIG. 18 exceptthat the fixation of the clay powder M and the formation of the inkimage are switched around but are identical to those of the ink jetrecording apparatus shown in FIG. 17.

FIG. 19 shows another modification of the ink jet recording apparatusshown in FIG. 17. The ink jet recording apparatus shown in FIG. 19employs a clay liquid N instead of the clay powder M employed in the inkjet recording apparatus shown in FIG. 17. The ink jet recordingapparatus shown in FIG. 19 has a clay liquid reservoir 24 which holds aclay liquid N that is prepared by dispersing a clay powder composed ofan epoxy resin binder and an intercalation compound into an insulatingsolvent such as of dibutyl phthalate or the like. The clay liquid N istriboelectrically charged to a potential ranging from -3˜-4 kV, forexample, while a bias potential (e.g., +300˜+400 V) that is of anopposite polarity to the clay liquid N is being applied to the clay drum20 and a bias potential ranging from +3˜+4 kV, for example, is beingapplied to the clay attaching roller 22. When the recording medium 2 isfed between the clay drum 20 and the clay attaching roller 22, therecording medium 2 is charged to an opposite polarity to the clay liquidN by the clay attaching roller 22, and the clay liquid N is attached tothe recording medium 2 under electrostatic forces acting between therecording medium 2 and the clay liquid N. Then, the recording medium 2to which the clay liquid N is attached is heated to a temperatureranging from 50° to 200° C. by a heater 25, whereupon the clay liquid Nis dried and fixed to the recording medium 2, thus forming a dyeacceptor layer X on the recording medium 2. The recording medium 2 withthe dye acceptor layer X thus formed thereon is fed by sheet feedrollers 26 to a subsequent printing section where an image is formed onthe recording medium 2 with an ink by the print head 1.

FIG. 20 is a view showing in its entirety an ink jet recording apparatusaccording to a yet still further embodiment of the present invention. Inthe ink jet recording apparatus shown in FIG. 20, a dye acceptor layer Xformed in a ribbon P is thermally transferred onto a recording medium 2to form the dye acceptor layer X on the recording medium 2. FIG. 21A and21B are views illustrative of the manner in which the dye acceptor layerX formed in the ribbon P is thermally transferred onto the recordingmedium 2.

As shown in FIG. 21A, the ribbon P for use in the ink jet recordingapparatus comprises a successively laminated structure composed of abase film 27, a dye acceptor layer X, and an adhesive layer 28. It waspossible to produce the ribbon P as follows:

20 g of synthetic smectite (tradename "SWN" manufactured by CoopChemical Co. Ltd.) was dispersed and swollen in one liter of water. Tothe dispersion, there was added the same amount of ethanol as thedispersion. While stirring the mixture, 0.65 g (1 mg equivalent) oftetra-n-decylammonium bromide dissolved in 200 ml of ethanol was droppedinto the mixture. After being left for one day, the aggregatedprecipitate was filtered out and cleaned with ethanol, removingquaternary ammonium salt. The cleaned precipitate was dried at 70° C.into a purely white powder. 20 g of the produced powder was charged into120 g of an ethanol solution containing 10 weight % of hydroxypropylcellulose, and dispersed by a roll mill for two days, thus producing asuspension. To the suspension were added 2 g of trifunctional isocyanate(Colonate HL manufactured by Nippon Polyurethane Co., Ltd.) and 1 g ofan ultraviolet light absorber (Seesolob 101S manufactured by CiproChemical Co., Ltd.), thereby producing a composition for forming a dyeacceptor layer.

A PET film having a thickness of 6 μm and including a surface processedfor releasability was prepared as a base film. The processed surface ofthe PET film was coated with a composition for forming a dye acceptorlayer by a wire bar, and dried with hot air at 120° C. for five minutes,thereby forming a dye acceptor layer in the form of a solid film havinga thickness of 5 μm.

Then, an adhesive composed of 2 parts by weight of vinylidene chloride -acrylonitrile copolymer (manufactured by Aldrich Corp.) and 20 parts byweight of methyl ethyl ketone was prepared, and coated on the dyeacceptor layer using a bar coater, to a wet thickness of 50 μm. Thecoated adhesive was then dried into an adhesive layer.

In this manner, the ribbon P as shown in FIG. 21A was produced.

The ink jet recording apparatus shown in FIG. 20 comprises, as a dyeacceptor layer forming means, a ribbon holding means (not shown) forholding a ribbon P in the recording apparatus, a heat roller 29 forheating the ribbon P which is drawn from the ribbon holding means, acooling roller 30 for cooling the ribbon P after a dye acceptor layer Xis thermally transferred, a peeling roller 31 for peeling a base film 27of the ribbon P from the dye acceptor layer X, and platen rollers 32through 34 for pressing a recording medium 2 against the ribbon P. Theink jet recording apparatus also has a serial print head 1 disposedsubsequently to the dye acceptor layer forming means.

The ink jet recording apparatus shown in FIG. 20 was operated to form animage on a recording medium 2 of synthetic paper having a thickness of100 μm as follows: The ribbon P and the recording medium 2 were set inthe recording apparatus such that the adhesive layer 28 of the ribbon Pconfronted the recording medium 2. The ribbon P and the recording medium2 were fed at a rate of 3 cm/second between the heat roller 29 heated to120° C. and the platen roller 32, so that the ribbon P and the recordingmedium 2 were heated and pressed, bonding the dye acceptor layer X ofthe ribbon P to the recording medium 2 through the adhesive layer 28. Atthis time, the dye acceptor layer X was bonded to the recording medium 2over its full width (in a direction perpendicular to the direction offeed of the recording medium 2). Then, the ribbon P and the recordingmedium 2 were cooled to room temperature by the cooling roller 30, andthe base film 27 of the ribbon P was peeled off the dye acceptor layer Xbonded to the recording medium 2 by the peeling roller 31. In thismanner, the dye acceptor layer X was thermally transferred from theribbon P to the recording medium 2 as shown in FIG. 21B. On therecording medium 2 with the dye acceptor layer X thermally transferredthereto, there was formed an image with an ink having the followingcomposition by the print head 1:

    ______________________________________                                        (Ink composition)                                                             ______________________________________                                        Basic dye            2 parts by weight                                        P-toluenesulfonic acid soda                                                                        2 parts by weight                                        Diethylene glycol   20 parts by weight                                        Polyethylene glycol 20 parts by weight                                        Water               50 parts by weight.                                       ______________________________________                                    

Basic dyes for respective colors Y, M, C, B were as follows:

(Dyes)

Y: C. I. basic yellow 51

M: C. I. basic red 23

C: C. I. basic blue 75

B: C. I. basic black 2.

A high-quality image having a circular dot shape was thus formed.

The produced image was immersed in water for one day and night, andthereafter the surface of the image was pressed strongly and rubbed by afinger. However, no dye was eluted, and no dye acceptor layer wasseparated from the dye acceptor layer, indicating that the image hadgood fixability. Furthermore, the image was exposed to Xe light (90000kJ/m²) at 30° C. and 65% RH. The remaining dye of each of the colors was80% or greater, indicating that the image exhibited a high level oflight resistance comparable with silver-salt photographs.

FIG. 22 shows a modification of the ink jet recording apparatus shown inFIG. 20. In the ink jet recording apparatus shown in FIG. 22, after adye acceptor layer X has been formed on a recording medium 2 by thermaltransfer, an image is formed on the recording medium 2 by a line printhead 1L. The other details of the ink jet recording apparatus shown inFIG. 22 are identical to those of the ink jet recording apparatus shownin FIG. 20. Since the ink jet recording apparatus shown in FIG. 20allows the dye acceptor layer X to be easily formed on the recordingmedium over its full width, it also may have a line print head 1L as isthe case with the ink jet recording apparatus shown in FIG. 22.

FIG. 23 shows an ink jet recording apparatus in which a dye acceptorlayer X is formed on a recording medium 2 using a ribbon P as with theink jet recording apparatus shown in FIG. 20. In the ink jet recordingapparatus shown in FIG. 23, the ribbon P is wound in a ribbon cassette35 which is mounted on a cassette holder 36 that has a heater (notshown), and the dye acceptor layer X of the ribbon P drawn from theribbon cassette 35 can be thermally transferred to the recording medium2 by the heater of the cassette holder 36. The ink jet recordingapparatus shown in FIG. 23, therefore, makes it possible to form a dyeacceptor layer only in a certain print region, and hence can be reducedin size.

The cassette holder 36 which holds the ribbon cassette 35 that storesthe ribbon P may be integral with a serial print head 1 for achieving afurther reduction in the size of the ink jet recording apparatus. Inthis arrangement in which the ribbon P is stored in the ribbon cassette35, the print head may comprise a line print head.

FIG. 24 shows an ink jet recording apparatus in its entirety in which afixing agent Q that contains an intercalation compound dispersed in waxand is solid at normal temperature is melted and coated on a recordingmedium 2 thereby to form a dye acceptor layer on the recording medium 2.FIG. 25 is a cross-sectional view of the ink jet recording apparatus.

The ink jet recording apparatus shown in FIG. 24 comprises, as a dyeacceptor layer forming means, a solid fixing agent cassette 37 forholding a solid fixing agent Q such that the solid fixing agent Q ispressed against a heat roller 38, a heat roller 38 for melting the solidfixing agent Q with heat and coating the melted solid fixing agent Q ona recording medium 2 upon rotation in the direction indicated by thearrow, and a pressing roller 39 positioned opposite to the heat roller38 and rotatable in the direction indicated by the arrow for pressingthe recording medium 2. The ink jet recording apparatus shown in FIG. 24also has a serial print head 1 subsequently to the dye acceptor layerforming means.

Before the ink jet recording apparatus shown in FIG. 24 is used, twosolid fixing agents Q-1, Q-2 were produced as follows:

(Solid fixing agent Q-1)

75 g of synthetic smectite (tradename "SW" manufactured by Coop ChemicalCo. Ltd.), 22.5 g of carnauba wax (manufactured by Toyo Petrolite Co.,Ltd.), and 52.5 g of paraffin wax (tradename "HNP-3" manufactured byNippon Seiro Co., Ltd.) were kneaded by a roll mill at 120° C. for fourhours, and left at normal temperature, thereby producing a solid fixingagent Q-1.

(Solid fixing agent Q-2)

150 g of synthetic smectite (tradename "SW" manufactured by CoopChemical Co. Ltd.) was charged into 1 kg of an ethanol solutioncontaining 10% by weight of polyvinyl butyral (tradename "BL-1"manufactured by Sekisui Chemical Co., Ltd.), and dispersed therein by aroll mill for two days, thus producing a suspension. Then, thesuspension was placed in a drying furnace at 110° C., producing a solidfixing agent Q-2.

The ink to be used in the recording apparatus was prepared according toa composition as follows:

    ______________________________________                                        (Ink composition)                                                             ______________________________________                                        Basic dye           2 parts by weight                                         Glycerin            2 parts by weight                                         Diethylene glycol   6 parts by weight                                         Water              30 parts by weight.                                        ______________________________________                                    

Basic dyes for respective colors Y, M, C, B were as follows:

(Dyes)

Y: C. I. basic yellow 2

M: C. I. basic red 46

C: C. I. basic blue 3

B: C. I. basic black 2.

Using the solid fixing agents Q-1, Q2 and the ink thus prepared, animage was formed on a sheet of plain paper by the ink jet recordingapparatus shown in FIG. 24. The heat roller 38 was set to a temperature(80°˜120° C.) equal to or higher than the melting points of the solidfixing agents, and the linear pressure between the rollers was set to 3kg/cm. The heat roller 38 and the pressing roller 39 were rotated at aspeed of 10 mm/s. As a result, an image was formed well on a dyeacceptor layer which was formed using either the solid fixing agent Q-1or the solid fixing agent Q-2.

FIG. 26 is a cross-sectional view of an ink jet recording apparatusaccording to a further embodiment of the present invention. The ink jetrecording apparatus melts a solid fixing agent Q and coats the meltedsolid fixing agent Q on a recording medium 2 to form a dye acceptorlayer thereon.

In the ink jet recording apparatus shown in FIG. 26, the solid fixingagent Q is melted and coated on the recording medium 2 as follows: Thesolid fixing agent Q is placed in a solid fixing agent cassette 40 witha heater, and the solid fixing agent Q which is melted is dischargedfrom the bottom of the solid fixing agent cassette 40 onto the recordingmedium 2 which is being fed in the direction indicated by the arrow.Then, the fixing agent Q on the recording medium 2 is uniformly squeezedinto a dye acceptor layer X having a predetermined thickness by asqueezer 41. An image is thereafter printed on the dye acceptor layer Xby a print head 1. The linear pressure of the squeezer 41, which dependson the viscosity of the solid fixing agent Q in a melted state, may beof about 0.5 kg/cm, for example.

While the ink jet recording apparatus according to various embodimentsof the present invention have been described above, the presentinvention is not limited to the above embodiments, but may be modifiedin any of various other arrangements. For example, the ink jet recordingapparatus may be arranged as a serial printer, a line head printer, orthe like in the embodiment in which the fixing solution is expelled orsprayed from the nozzle or nozzles to form a dye acceptor layer on therecording medium 2, the embodiment in which the fixing solution iscoated by a coating roller to form a dye acceptor layer on the recordingmedium 2, the embodiment in which the clay powder is applied to form adye acceptor layer on the recording medium 2, the embodiment in which adye acceptor layer is formed on the recording medium 2 by beingthermally transferred from the ribbon, and the embodiment in which thesolid fixing agent is melted and coated to form a dye acceptor layer onthe recording medium 2.

When the fixing solution is expelled or sprayed from the nozzle ornozzles, the solvent of the fixing solution tends to evaporate, cloggingthe nozzle or nozzles. It is therefore preferable to mix a solventhaving a low vapor pressure as a clogging inhibitor with the fixingsolution. Such a solvent for use as a clogging inhibitor shouldpreferably:

(1) be able to be mixed with another solvent and chemically stable insuch another solvent;

(2) have a low vapor pressure (e.g., 0.11 nmHg or lower); and

(3) be not frozen at low temperatures.

Such a solvent (clogging inhibitor) may be a nitrogen-containing solventsuch as a glycol such as ethylene glycol, propylene glycol, diethyleneglycol, triethylene glycol, tetraethylene glycol, polyethylene glycol,or glycerin, a glycol ether such as ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methylCarbitol, ethyl Carbitol, butyl Carbitol, ethyl Carbitol acetate,diethyl Carbitol, triethylene glycol monomethyl ether, triethyleneglycol monoethyl ether, or propylene glycol monomethyl ether, an amidesuch as triethanolamine, formamide, or dimethyl formamide, or apyrrolidone such as N-methyl-2-pyrrolidone.

The content of the clogging inhibitor, which differs in differentcircumstances, should generally be 3% or more of the total weight of thefixing solution, and preferably be in the range of from 3% to 90% of thetotal weight of the fixing solution.

In the embodiments, the dye acceptor layer is formed substantially atthe same time that an image is printed on the recording medium 2.However, the dye acceptor layer may be formed in advance on therecording medium 2.

However, it is necessary to adjust the surface tension and viscosity ofthe fixing solution to be expelled or sprayed from the nozzle or nozzlesdifferently in the case where the dye acceptor layer is formedsubstantially at the same time that an image is printed on the recordingmedium and in the case where the dye acceptor layer is formed in advanceon the recording medium.

Specifically, if the dye acceptor layer is formed substantially at thesame time that an image is printed on the recording medium, then afixing solution with a solid content of a lower proportion, i.e., afixing solution having a lower viscosity, is used than if the dyeacceptor layer is formed in advance on the recording medium.

More specifically, if the dye acceptor layer is formed in advance on therecording medium, then a fixing solution composed, for example, of:

    ______________________________________                                        intercalation compound: smectite                                                                        150 g                                               binder resin: butyral     100 g                                               solvent: ethanol          900 g                                               ______________________________________                                    

with a solid content having a proportion of 21.7% is used. If the dyeacceptor layer is formed substantially at the same time that an image isprinted on the recording medium, then a fixing solution composed, forexample, of:

    ______________________________________                                        intercalation compound: smectite                                                                    75 g                                                    binder resin: butyral 25 g                                                    glycol: ethylene glycol                                                                             30 g                                                    solvent: ethanol      520 g                                                   ______________________________________                                    

with a solid content having a proportion of 15.4% is used.

At any rate, the same ink can be used.

The ink jet recording apparatus according to the present invention canform images of excellent water resistance and light resistance.

We claim:
 1. An ink jet recording apparatus comprising:an ink nozzle forexpelling an ink toward a recording medium to form an image thereon; anddye acceptor layer forming means for forming on said recording medium adye acceptor layer composed of an intercalation compound which fixes andholds a dye of said ink by way of an intercalation, wherein said dyeacceptor layer forming means forms the dye acceptor layer by coating afixing solution containing said intercalation compound on said recordingmedium with a coating roller.
 2. An ink jet recording apparatuscomprising:an ink nozzle for expelling an ink toward a recording mediumto form an image thereon; and dye acceptor layer forming means forforming on said recording medium a dye acceptor layer composed of anintercalation compound which fixes and holds a dye of said ink by way ofan intercalation, wherein said dye acceptor layer forming meanscomprises means for electrically charging either a clay powder or a clayliquid composed of said intercalation compound and a thermoplastic resinand said recording medium to respective opposite polarities to causesaid clay powder or said clay liquid respectively to beelectrostatically attached to said recording medium, and means forheating and fixing said clay powder or said clay liquid to saidrecording medium.
 3. An ink jet recording apparatus, comprising:an inknozzle for expelling an ink toward a recording medium to form an imagethereon; and dye acceptor layer forming means for forming on saidrecording medium a dye acceptor layer composed of an intercalationcompound which fixes and holds a dye of said ink by way of anintercalation, wherein said dye acceptor layer forming means comprisesribbon holding means for holding a ribbon composed of a base film andsaid dye receptor layer formed thereon, means for drawing said ribbonfrom said ribbon holding means, and heating means for thermallytransferring the dye acceptor layer of the ribbon drawn from said ribbonholding means onto said recording medium.
 4. An ink jet recordingapparatus according to claim 3, further comprising a line print head forprinting said recording medium with said dye acceptor layer formedthereon.
 5. An ink jet recording apparatus according to claim 3, whereinsaid ribbon holding means comprises a ribbon cassette with said ribbonwound therein, and said heating means comprises a heater disposed in acassette holder for holding said ribbon cassette.
 6. An ink jetrecording apparatus, comprising:an ink nozzle for expelling an inktoward a recording medium to form an image thereon; and dye acceptorlayer forming means for forming on said recording medium a dye acceptorlayer composed of an intercalation compound which fixes and holds a dyeof said ink by way of an intercalation, wherein said dye acceptor layerforming means melts a solid fixing agent composed of said intercalationcompound and a wax, and coats the melted fixing agent on said recordingmedium.